Plugin Directory

Forms for Mailchimp by Optin Cat – Grow Your MailChimp List

Forms for Mailchimp by Optin Cat – Grow Your MailChimp List


MailChimp Optin Cat WordPress Plugin

Forms for Mailchimp by Optin Cat is a super-fast tool that lets you build beautiful looking MailChimp forms to maximize conversions and grow your mailing list.

Gutenberg Compatible

This plugin is fully compatible with WordPress 5.0’s new content editor (“Gutenberg”). Simply create your MailChimp form, then add your MailChimp block to your website.

In just two minutes, you can build a MailChimp form that is fully optimized and customized to fit your theme’s design.

Optin Types

Forms for Mailchimp by Optin Cat allows you to build a range of MailChimp forms. These include:

  • MailChimp post boxes – MailChimp forms that you can add to your various posts or pages. Can also be added to your site as a MailChimp block using WordPress 5.0’s new content editor.
  • MailChimp sidebar widgets – Widgets that will sit in your sidebar so that they’re present across your entire site
  • MailChimp lightbox pop-ups – Pop-up forms that appear over the top of your content and allow your visitors to put in their details that way

You’ll also be able to create an unlimited number of these forms for your site.


Here are some other cool features that Forms for Mailchimp by Optin Cat comes with

  • Responsive design. Your MailChimp forms will never look out of place, no matter which device your visitors are using.
  • Post boxes can be added with a shortcode, Gutenberg MailChimp block, or automatically at the bottom of posts/pages.
  • Lots of customization options. Choose between font sizes, colors and more.
  • Intuitive and elegant interface that keeps things quick and easy.
  • Analytics feature let’s you know which MailChimp forms work and which ones don’t.
  • Conversion optimization best practices built-in – Forms for Mailchimp by Optin Cat is the work of experienced marketers who know what makes people convert.

In no time you’ll be creating amazing MailChimp newsletter forms that never let you down and that capture thousands of e-mails.

Why bother?

Your MailChimp list is one of your most important assets, no matter if you’re a blogger, marketer or small business owner. Rely on Forms for Mailchimp by Optin Cat to build great looking forms that convert.


You’ll need a self-hosted WordPress.org site and a MailChimp account – sign up for a free MailChimp account here. Integration is fast and seamless, no coding skills required.

Optin Cat Premium

Forms for Mailchimp by Optin Cat Premium hels you grow your list with the following features:

Mobile MailChimp popups.

MailChimp single optin feature (disable double optin).

Lots of extra layout & design options.

Smart popup targeting.

Mobile Campaign Monitor popups.

Two Step Optins: Trigger a popup after the user clicks on a hyperlink.

Optin Bait Delivery: Send optin baits straight from WordPress.

Exit Intervention: Display popups when the user is about to leave your site.

Attention grabbing Popup Effects.

Priority email support.

Learn more about Forms for Mailchimp by Optin Cat Premium >>

Privacy Disclosure

This plugin stores personal data (eg. names & emails collected using this plugin) in the WordPress database.

This plugin integrates with the WordPress GDPR privacy controls for data export & data deletion added in WordPress 4.9.6.

This plugin uses a browser cookie to track successful optins.

This plugin can be configured to connect to 3rd party service providers such as MailChimp.

If you use this plugin to connect to a 3rd party, personal data may also be shared with that party.

Additional privacy policy information for 3rd party services can be found here:


Our full privacy policy is available here: https://fatcatapps.com/legal/privacy-policy/


  • Examples of the MailChimp form designs
  • The MailChimp Opt-in Form Builder
  • MailChimp Post Box
  • MailChimp Popup
  • Another MailChimp Post Box
  • MailChimp Form Analytics
  • The entire settings screen



  • Optin Cat Form
  • Optin Cat Two-Step Optin


  1. Upload the plugin to the /wp-content/plugins/ directory
  2. Activate the plugin through the ‘Plugins’ menu in WordPress
  3. In your sidebar, select ‘Optin Cat -> Add New’ to create a new MailChimp form.
  4. Choose Sidebar Widget, Post Box or Popup – MailChimp form


Do I need a MailChimp account?

Yes, you need a MailChimp account. You can sign up for a free MailChimp account here.

Do I need to set up a list in MailChimp to use this plugin?

Yes, you’ll need to set up at least one MailChimp list.

How to integrate this plugin with MailChimp?

  1. Go to your Dashboard -> Optin Cat -> Add New or Select your previously created form.
    To integrate your MailChimp form with your MailChimp account please follow the steps below.

  2. Go to your Dashboard -> Optin Cat -> Add New or select a previously created MailChimp form.

  3. Go to Email Marketing Provider section -> enter your MailChimp API key.

  4. Enter your MailChimp API key in to the field.

  5. If you entered the correct MailChimp API key, a green checkmark will appear. Otherwise, a red error sign will appear. If this is the case, please double check your MailChimp API key.

  6. A dropdown will now appear. Select your MailChimp List that you would want your MailChimp form to populate.

Where to find my MailChimp API Key?

You can find your MailChimp API key here.

How to add my MailChimp list?

After entering the correct MailChimp API key a dropdown containing all of your MailChimp lists will appear. Select the MailChimp list of your choice there.

How to set up MailChimp single optin?

This feature is only part of the premium version of this plugin. For more information, click here.

The plugin redirects to the Thank You – page but subscribers are not added to my MailChimp list?

Keep in mind that MailChimp will send a confirmation email before adding subscribers to your MailChimp list. This email could be delayed by a couple of minutes or end up in your spam folder.

If you’re sure that subscribers aren’t added to MailChimp, please check with your host if they have PHP CURL installed and if they allow requests to https://api.mailchimp.com/.

Does this plugin work with MailChimp groups?

Not at this time. We might add support for MailChimp groups in the future if there’s popuplar demand for it. If you’d like to see this feature, please leave a comment in the suppport forum.

How to add MailChimp forms to my site?

You can add MailChimp optin forms to your site by going to Optin Cat -> Add New.

First you’ll have to choose a MailChimp form type – sidebar widget, post box (goes inside of a WordPress post or page), or lightbox popup.

Then choose a layout and modify the text, colors and design using the point & click editor.

Afterwards, connect the from to the MailChimp API and select a Thank You page.

Finally, publish your MailChimp form. This varies based on the MailChimp form type – instructions can be found in the user interface.

Which MailChimp form-type is right for me?

If your blog has a sidebar (like most blogs), you should definitely set up a MailChimp form and place it at the top of your sidebar. This is a quick & easy win.

Adding a MailChimp post box to the bottom of your blog posts is highly recommended. Readers are highly engaged after reading a post and will be more likely to opt in. For extra effectiveness, you could set up individual MailChimp forms with unique call to actions & text for each category. This will result in even more MailChimp subscribers.

The most effective way to grow your list is our MailChimp popup. This MailChimp form is a lot more agressive than sidebar widgets & post boxes so it should be used with care. The premium version of this plugin comes with some advanced settings that let you fine-tune the popup further so you can maximize conversions while not annoying your users.

To recap, the most effective & aggressive MailChimp form is the popup. The MailChimp post box will get you less conversions, but it’s a lot more subtle. Finally, the MailChimp sidebar widget will most likely get you the least conversions. Nonetheless, it’s worth setting up since it’s a quick and easy win.

How to create & publish a MailChimp sidebar widget?

To create your MailChimp Sidebar widget:

  1. Go to your Dashboard -> Optin Cat -> Add New.

  2. Select “Widgets” and choose a Layout.

  3. Configure your MailChimp form’s design, email marketing provider integration and “Thank You”-page. Hit save.

  4. Go to Appearance -> Widgets -> Select and add the Optin Cat Widget to your sidebar. Then select your MailChimp form,

  5. Click save and view changes on your website afterwards.

How to display a MailChimp sidebar widget using a shortcode?

You can display a MailChimp widget by using this shortcode:
[optin-cat id=1361]

Replace 1361 with the post id of your MailChimp sidebar widget. (What is my post id?)

How to disable impression & conversion tracking?

Simply add define( 'FCA_EOI_DISABLE_STATS_TRACKING', TRUE); to your theme’s functions.php file.

How to create & publish a MailChimp post box?

Post Boxes are MailChipm optin forms that can be added to posts or pages.

  1. Go to your Dashboard -> Optin Cat -> Add New

  2. Click Post Boxes and choose a Layout you like.

  3. Configure your MailChimp Post Box design.

  4. Set up a “Thank You” page.

  5. To deploy your MailChimp Post Box, scroll to the “Publication” section.

5a. You can deploy your MailChimp Post Box using a shortcode. Copy your shortcode and paste it anywhere on your site.

5b. Or, you can deploy your Post Box by automatically appending it to the bottom of all or certain posts, pages, and categories.

  1. Hit save and check your website.

How to display a MailChimp post box in my template files?

You can display shortcodes using echo do_shortcode($content).


How to create & publish a MailChimp popup?

Here’s how you create a MalChimp popup.

  1. Go to your Dashboard -> Optin Cat -> Add New.

  2. Click Popups and click on the Layout of your choice.

  3. Configure your MailChimp Popup design.

  4. Set up a “Thank You” page.

  5. To deploy your MailChimp Popup, scroll to the “Publication” section.

The MailChimp Popup comes with the following targeting options:
Show MailChimp popup (frequency)
Time on page is at least X seconds.

Optin Cat Premium only:
Number of pageviews during this visit is at least X.
Scrolled down on current page at least X%.
Only show MailChimp popup on the following posts/pages/categories.
Never show MailChimp popup on the following posts/pages/categories.
Exit intervention (only part of Business + Elite plans).

How to add custom CSS to my MailChimp form?

Go to Optin Cat -> Powerups and enable Custom CSS. Then go and edit your MailChimp form – you’ll now find a CSS textbox.

What is the New CSS powerup?

This powerup is part of Forms for Mailchimp by Optin Cat for the sake of users that installed this plugin before June 2015. For better mobile & tablet compatibility we decided to rewrite all our CSS from scratch. This setting gives you the ability to use our old CSS instead (not recommended).

Do your MailChimp forms work on mobile devices?

Yes. MailChimp Post Boxes & MailChimp Widgets work on all devices. MailChimp Popups will not be displayed on mobile devices if you use the free plugin.
The premium version comes with mobile MailChimp popups that look great on all devices.

How does the “no CSS” MailChimp form work?

This MailChimp form is available as a MailChimp post box & widget and is made for developers. This form will inherit your theme’s styling. Most likely you’ll have to add some custom CSS to make the form look great.

How does the MailChimp form analytics feature work?

This plugin tracks all impressions and conversions of your MailChimp forms, even if your site is cached. Your MailChimp form analytics will be displayed as a beautiful graph in your WordPress dashboard, plus you can view each individual form’s stats by going to Optin Cat -> All Optin Forms. You can also reset the stats of each MailChimp form by going above screen, hovering over the form and clicking “Reset Stats”.

Do I need to set up a thank you page? How does it work?

Whenever a MailChimp form was sucessfully submitted, the new subscriber will be redirected to a thank you page.
A Thank You page is a normal WordPress page. It’s recommended that you add some text like “Thanks for subscribing, please check your email”. Even better, you could add some further call to action such as “like us on Facebook” or “check out our products”.

Setting up a Thank You page is required.

What are the differences between Forms for Mailchimp by Optin Cat Free & Premium?

Forms for Mailchimp by Optin Cat Premium hels you get more subscribers with the following features:

Mobile MailChimp popups.

Smart Popup Targeting.

MailChimp single optin.

Lots Of Additional Beatiful Layout & Design Options.

Two Step Optin Feature: Trigger a Mailchimp Popup Optin Form after the user clicks on a hyperlink.

Optin Bait Delivery: Send Optin Baits straight from WordPress.

Exit Intervention: Display popups when the user is about to leave your site.

Priority Email Support.

Learn more about Forms for Mailchimp by Optin Cat Premium >>


2020 年 10 月 23 日 1 回复
Very good and unique plugin, excellent support
2020 年 4 月 11 日 1 回复
This is exactly what I was looking for.


“Forms for Mailchimp by Optin Cat – Grow Your MailChimp List” 是开源软件。 以下人员对此插件做出了贡献。




  • Fix reported security vulnerability with admin dismissal notice


  • Fixed/added PHP 8.2 Compatibility
  • Updated Icon
  • Fixed Gutenberg block
  • Fixed HTML escaping in admin (potential XSS vulnerability)
  • Tested up to WordPress 6.3


  • Fixed error message in Publication metabox
  • Fixed some other issues in Optin Cat Premium
  • Tested up to WordPress 5.8


  • Updated feedback form
  • Tested up to WordPress 5.6.2


  • Updated display name
  • Tested up to WordPress 5.6


  • Tested up to WordPress 5.5.0


  • Add color pickers for “Thank you” message
  • Add color picker for bottom half of forms for relevant layouts
  • Add Gutenberg block for two-step optins (Premium only)
  • Allow form navigation with Tab key
  • Allow ActiveCampaign existing users to be updated
  • Allow optin forms to work without email provider (store locally) (Premium only)
  • Replace 3rd party Codemirror for builtin one
  • Replace TinyMCE for simple text editor
  • Fix preview form live updates
  • Fix missing color picker labels
  • Fix alignment issue with TwentyTwenty theme
  • Fix optin bar display issue in IE
  • Tested up to WordPress 5.4.2


  • Fix/optimize table creation
  • Tested up to WordPress 5.2.2


  • Fix MailChimp single optin setting not working
  • Remove unused onboarding code
  • Tested up to WordPress 5.1.0


  • Add WordPress 5.0 block (Gutenberg) support
  • Allow resubscribing to MailChimp (e.g. add interest groups to existing customer)


  • Fix potential error on activation
  • Tested up to WordPress 4.9.8


  • Fix name field not being sent if GDPR checkbox enabled
  • Fix GDPR checkbox not showing if description field is disabled


  • Added Subscribers table
  • Added GDPR compliance checkbox
  • Integrated with WordPress’ GDPR data export and erasure features


  • Added 2 new layout options
  • Added MailChimp single/double optin toggle to free plugin
  • Added descriptive names for each layout
  • Improved HTML formatting & bullets
  • Improved editor screenshots and styling
  • Improved default color palette for color pickers
  • Improved error messages
  • Changed menu position from 105 to 106 to fix conflict
  • Updated featherlight library to 1.7.9
  • Misc bug fixes


  • Update software licensing library


  • Add uninstall survey
  • Tested up to WordPress 4.8


  • Check if user is already subscribed to MailChimp before optin


  • Fix optin form JavaScript sometimes not being enqueued on post boxes


  • Added Success Cookie feature – stop showing optins to users that have already opted in
  • Rewrote targetting feature for improved compatibility
  • Fixed name and email field responsive scaling
  • Minified all CSS and JS files to improve performance


  • Fix popup rule backward compatibility issue where some settings would not save (Device & Go Live toggle)
  • Fix some text inputs having escape slashes around quotation marks
  • Changed delete rule button to always show
  • Changed add rule button to hide when all rules have been added
  • Removed ‘Never’ as a display frequency option – replaced with Go Live toggle


  • Added AJAX thank you message
  • Added setting to target popups based on device (desktop and/or mobile)
  • Added button hover color picker
  • Added width picker for Form, Button, Name, and Email fields
  • Added placeholder colors based on font colors for email and name
  • Added show/hide toggle to Headline, Description, Privacy Policy sections
  • Improved visual editor behavior and design
  • Improved UI of popup targetting rule builder
  • Changed Privacy Policy area to “After Button Area”
  • Changed subscribing animation to simple text
  • Changed various texts in UI
  • Fix rare case of ‘one a month’ and ‘only once’ display cookie date possibly being invalid


  • Fix “Class ‘K’ not found” error some users reported on activation


  • Fix Power Up settings potentially getting reset on activation


  • Merged Power Ups and Licensing page in to one with improved UI
  • UI updates
  • Up to 15% improved performance


  • Update Tooltipster library to latest version for better compatibility
  • Change API inputs to activate on any input (e.g. paste)
  • Fix editor not working on Safari
  • Fix metaboxes potentially being hidden by WordPress


  • (Only released for GetResponse and premium)


  • Fix button hover color being white on new forms
  • Fix potential PHP issue ‘Can’t use function return value’


  • Performance improvements of up to 50%
  • UI Updates
  • Fix inconsistent loading of previous settings (API keys/mailing lists) when creating a new form
  • Revert sending ‘unnamed user’ as user name if empty


  • Add auto-focus on popup
  • Change ‘Name’ placeholders to ‘First Name’
  • Fix MailChimp 10 lists maximum
  • Fix custom css box sometimes hidden for personal plan
  • Fix a FireFox popup display issue


  • Fix an issue with some icons being removed/hidden
  • Fix potential MailChimp issue with empty user names
  • Fix for potential encoding type being changed by theme


  • Fix an issue with saving forms a small number users reported


  • Each form can now be connected to a unique account (API key)
  • Performance improvements: All CSS is pre-compiled, Removed several deprecated .css files
  • Upgraded to use MailChimp API 3.0
  • Fixed a form saving issue that affected some PHP/WordPress installations
  • Fixed PHP warnings related to remove_meta_box()


  • Performance improvements: optin forms (particularily widgets) now load much faster


  • Bugfix: Optin Cat now works with multiple MailChimp accounts


  • Added spinning animation after form submission
  • Changed ajax error message (inside of button) into something more humanly readable
  • Numerous bug fixes


  • Fixed a JS bug introduced with 1.5.0


  • Improved performance of Optin Cat form editor in the WP backend (it now loads faster)
  • Impression tracking can now be disabled
  • Small UI improvements to Optin Cat form editor
  • Numerous bug fixes


  • Bugfix: Fixed a conflict with the Beaver Builder plugin
  • Various other small bugfixes & improvements


  • Changed: Updated layout selection screen to be responsive and look more like WordPress theme select screen.
  • Fixed: Hide Optin Cat shortcode insert button and dashboard widget from users with privileges below editor (subscriber and author).
  • Fixed: Logged in users no longer count towards impressions on forms.


  • Fixed: A bug in our MailChimp popup targeting engine caused the “display once per month” criteria to not work as expected in some cases, which kinda defeated the purpose of our fancy targeting engine.
  • Fixed: MailChimp Forms by Optin Cat caused a site’s W3 HTML validation to fail due to the placement of the style tag. This wasn’t a big problem (all browsers always rendered Optin Cat properly), but not ideal.


  • Fixed an issue related to bots causing fake conversion data.


  • Tiny fix: Ignore shortcode if the global $post is empty


  • Fixed a bug in the Popup targeting engine introduced in MailChimp Forms by Optin Cat 1.3.5.


  • Improved MailChimp Popup targeting engine: changed how a session is counted (a session now expires after 30 minutes of inactivity).


  • Improved MailChimp Popup targeting engine for better performance.
  • Improved MailChimp Post Box targeting: only one box can be displayed at the bottom of the post at any given time going forward. The most exactly targeted post box will be given priority (eg. Individual Post > Category > All Posts)


  • Performance improvements
  • Minor Bugfixes


  • Fixed a bug that caused display issues on some sites after unchecking the “New CSS” powerup


  • Fixed a bug that caused some conversions to be tracked more than once


  • Added Analytics feature
  • Added tinyMCE button to WP Post editor
  • Improved Optin Editor UI
  • Various minor bugfixes
  • Added the ability to customize error text
  • Fixed a bug that displayed not-mobile friendly popups on some mobile devices


  • Bugfix: “Quick edit” disappears on pages
  • Improved performance / loadspeed of popup feature
  • Improved performance of WP backend


  • Renamed plugin to Optin Cat
  • Added new layout
  • Added MailChimp Popup Feature
  • Numerous Bugfixes
  • Numerous User Interface Improvements


  • Fixed bugs introduced with 1.1.3


  • CSS improvements
  • UI improvements
  • Fixed API conflicts
  • Fixed conflict with cherry plugin


  • Numerous CSS Fixes
  • Fixed issues with PHP5.2
  • Confirmed compatibility with WordPress 4.0.1
  • Added Easy Opt-ins Premium banner


  • Fixed an issue that was introduced with v1.1


  • Added new opt-in type: Post Boxes which can be published using shortcodes.
  • Added 2 new widget layouts.
  • Added 2 new post box layouts.
  • Added Custom CSS power-up.
  • Added “No CSS” layouts.
  • Lots of UI improvements.


  • Updated readme.txt.
  • Updated MailChimp API integration


  • Added screenshots


  • Updated readme.txt.


  • Added “Tested up to: 4.0”


  • Initial release


  • Beta release